Giving Money to New Moms Can Boost Baby Brain Activity, Study Says

A baby's brain development and how much money their parents make may not seem connected, but researchers have long known poverty can have a negative effect on cognitive development, educational attainment and future earning potential.

A recent study found giving monthly cash payments—like the Child Tax Credit American families received in 2021—to low-income mothers had a positive impact on their babies' brain activity.

The study, published in January 2022 in the journal Proceedings of the National Academy of Sciences, pulled data from the Baby's First Years (BFY) study, the first randomized control trial of the effects of poverty reduction on children's brain development in the United States. Beginning in 2018, BFY researchers recruited 1,000 low-income moms shortly after they gave birth, in four metropolitan areas: New York City; Omaha, Nebraska; New Orleans; and Minneapolis-St. Paul.

Most of the mothers were Hispanic or Black and reported household incomes of slightly more than $20,000 in the year prior to giving birth. They were randomized into two groups: One group received $333 per month, and the other group received $20 per month for the first 52 months of the child's life. The mothers were free to spend the money however they chose, without restriction or condition.

Around the babies' first birthdays in 2019, their brain activity was measured by visiting data collectors using electroencephalography (EEG) in their homes. Researchers collected data for only 435 babies in 2019, suspending data collection for 2020 and 2021 due to the COVID-19 pandemic. EEG measures two categories of electrical activity in the brain: power and frequency, which refers to how many times a brain wave repeats within a second, or how "fast" the brain activity is.

The study's authors wrote: "We hypothesized that infants in the high-cash gift group would have greater EEG power in the mid- to high-frequency bands and reduced power in a low-frequency band compared with infants in the low-cash gift group. Indeed, infants in the high-cash gift group showed more power in high-frequency bands."

Babies in the $333 per month group had higher-frequency activity than babies in the $20 per month group. They also had higher-power brain waves than infants in the low-cash gift group.

Researchers measured alpha, beta and gamma waves, but only the gamma-wave impact was statistically significant. Gamma waves are the fastest brain waves and are associated with learning, memory, attention and information processing.

The role of income and early intervention

"We know poverty is associated with a lot of things, from learning disabilities to lower school achievement," said Sanam Hafeez, Ph.D., a neuropsychologist in Queens in New York City. "A lot of that has to do with the fact that children don't control what neighborhood they live in or what family or environment or circumstances they might be born into. But there's always been a very clear, direct correlation between socioeconomic status and cognitive and academic advancement."

The 2022 study suggested that family income plays a significant role in early childhood development and affects particular parts of the brain, namely, the cerebral cortex, which supports language and executive functioning. From early childhood through adolescence, kids who come from families with higher incomes tend to score higher on a variety of cognitive and social-emotional assessments.

"The majority of the initial brain formation, the connections the brain makes, is achieved at the greatest level from birth to 3 years and then a little more until about 7 or 8 years," Hafeez said. "People's IQ really starts to become stable around age 6 or 7, which means that any intervention that you want to put in must be in the very early years."

Early childhood interventions include speech therapy, psychological counseling, preschool or even medication. An infusion of cash may be another one.

But money shouldn't replace other interventions, as the study's authors note: "[W]e do not suggest that a 12-month intervention alone would be likely to have lasting effects, nor that cash transfer policies obviate the need for direct service interventions, such as well-child pediatric visits, home visitation or high-quality early childhood education."

What's not clear from this first study is how the higher-cash infants' brain waves were affected in the way they were. How the mothers spent their money also wasn't included in this study, though the researchers noted this examination would be part of future BFY studies.

"We don't know the mechanism, but we do know it truly appears that this intervention causes changes in the brain," said Stephanie Merhar, M.D., a neonatologist at Cincinnati Children's Hospital in Ohio.

What's also not clear is whether this early intervention will translate to tangible results later in life.

"We have no idea. I mean, we suspect, based on previous literature, that these things will correlate with later actual outcomes," Merhar said.

"This is an intermediate step," Merhar added. "I'm excited to see what comes out next from the study, because I think it's pretty groundbreaking."